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Monday, 13 March 2017

Under Pressure

HEAT is a much more complicated armour penetration mechanism than traditional kinetic penetrators, and thus leads to more interesting experiments. For example, in this one, the objective of the test was to determine how effective ERA was at disabling the heat blast, but more importantly, what an ERA block detonation would do to the crew.

The trials were performed on a model simulating a tank with ERA. Rabbits inside the model simulated crew.

"9. An explosion of a reactive armour cassette does not noticeably affect the U-5TS gun barrel. An insignificant amount of fragments flies towards the turret.

10. When the reactive armour reacts with a striking shell and penetration is not achieved, a pressure wave inside the tank is not detected at crew positions.

11. The magnitude of the pressure of the wave detected by piezometers at crew positions almost does not depend on the mass of the charge (the payload varied from 0 to 2500 g) and ranges from 177 to 166 dB inside the model in various locations.

Biological trials showed that animals (rabbits) received light to medium injuries. However, existing data shows that pressure on the order of magnitude of 0.04-0.15 kg/cm², the measured range of pressure, are not harmful to humans. The pressure can be further reduced with a liner or a screen system.

12. In case of penetration with a HEAT jet, pressure waves with an amplitude of ~0.4 kg/cm² was registered inside the model."

Pressure of 0.4-0.6 kg/cm² is enough to cause medium injuries to a human, characterized by loss of consciousness, hearing damage, bleeding from the nose and ears, fractures, or twisting of limbs.